Body Adjusting to Diet?

Hi Everyone,

Just this past week (and by that I mean since Monday, so...two days), I've really cleaned up my diet. Previously I was at a higher calorie count and not focusing on eating nutritious foods - it was really just my goal to not gain any more weight, and heal a couple of injuries I had, get through some stressful stuff....you know, the time just wasn't right for weight loss.

Now though, I've bought myself a diet journal (cos I'm a paper and pen kinda gal) and I'm looking at my macros - mainly protein. I have other goals, like drinking plenty of water and eating a variety of fruits and vegetables.

But I'm lethargic. Not tired, like sleepy, but lethargic and lacking energy. I'm wondering if it's natural to experience this to a degree, since it must be a shock to my body. I haven't worked out the past two days, but I've been 'lightly active' - probably about half an hour of walking, taking the stairs etc.

Just cos I know someone will ask, here's what I ate yesterday:

Greek yogurt, vanilla protein powder, 10 almonds, 1/2c blueberries
Mixed bean chili
Grilled mushroom stuffed with quinoa, sardines and parmesan
Coffee light frappuccino
Protein shake with unsweetened almond milk
Total: 1679 cals

Today:
Instant unflavoured oats, 1c raspberries/blueberries, vanilla protein powder, unsweetened almond milk
Tuna nicoise salad
RAW cashew bar
Mocha light frappuccino with soy
Greek yogurt, tsp honey, 10 almonds
Dinner tbc

So...did anyone else get a kind of low-energy period when they switched to a healthy diet?